TWI516295B - Apparatus and method for monitoring an airway device such as an endotracheal tube - Google Patents

Description

Method for monitoring inflatable seal pressure of airway device, computer readable medium and device

The present invention relates to monitoring of airway devices, and more particularly to an apparatus and method for use in an airway or pharyngeal/throat device for maintaining airway opening in an animal or human patient.

A gas duct, or similar airway device, is used to maintain a clear airway in a patient, such as for artificial ventilation during surgery. The general device includes an inflatable arm pocket that inflates the patient's airway position. The inflatable arm pocket forms a seal between the airway device and the tissue surrounding the airway where it maintains the device in the airway of the patient and prevents leakage of oropharyngeal secretions into the patient's lungs.

The device described in the World Patent Application No. WO-A-99/33508 includes a monitoring system for monitoring the pressure of the arm pocket of the throat mask type airway device and for maintaining the preset pressure of the inflatable arm bag. Within the minimum tolerance. In particular, the apparatus periodically measures the pressure within the closed system containing the inflatable arm pocket and compares the measured pressure to a predetermined pressure to determine a difference value and its polarity. The device then controls the pressure within the closed system to reduce the difference value to near zero. The disclosure of the patent application No. WO-A-99/33508 is hereby incorporated by reference.

The object of the present invention is to provide an improvement of the device described in the patent application no. WO-A-99/33508.

According to a first aspect, the present invention is directed to a method for monitoring an inflation seal pressure of an airway device, the method comprising the steps of periodically receiving a pressure value indicative of an inflation seal pressure; The receiving pressure value and a preselected optimal air pressure value, and if the difference between the received pressure value and the preselected pressure value is greater than a preset tolerance, changing the inflation seal pressure to reduce the difference value; characterized by the change The rate at which the pressure step is performed depends on the difference between the value of the received pressure and the value of the optimum pressure.

In the prior art, the typical mode is the rapid reaction correction and the pressure deviation between the set points. However, intra-thoracic and intra-tracheal pressure during the breathing cycle of the patient causes a change in the circulating pressure of the inflatable seal. In certain situations, an immediate response correction to a pressure deviation due to a normal cycle change may cause the inflation pressure to decrease below the minimum required to create a seal within the airway. This in turn may cause leakage of secretions through the seal into the patient's lungs and increase the risk of the airway device deviating from the original position.

Therefore, the present invention can minimize the influence of the problem by controlling the pressure change rate after the deviation from the ideal pressure or the pressure change. Therefore, unlike the generation of an immediate pressure change correction deviation, the pressure adjustment rate is dependent on the deviation of the measured pressure value from the optimum air pressure value. The rate of adjustment can be further defined by a threshold value. By controlling the rate of pressure regulation, the time required to correct the deviation from the ideal value is also delayed. In a typical condition, the rate of adjustment produces a delay after a period of time, corresponding to or greater than the normal time interval of inspiration or exhalation, representing the maximum pressure deviation produced by the breathing cycle.

In one embodiment, the rate of pressure change is dependent on the square of the difference between the measured pressure value and the desired value.

For example, in one embodiment, a piston is used to change volume and increase pressure in a closed volume system, and the rate at which the piston moves is defined by the following equation: Where: P ₁ is the actual measured pressure S is the set point or ideal pressure * represents the multiplication operation R system adjustment constant

In one embodiment, the rate N is a speed corresponding to the number of steps of the stepper motor that drives the piston.

The rate N can vary with a predetermined maximum threshold speed. Therefore, if the calculated rate N is greater than the critical value, the control piston is moved at a critical rate.

In a typical condition, if the measured pressure is above the set point/ideal pressure, the motor drives the piston to retreat at a rate N to reduce the pressure, and if the measured pressure is below the set point, the motor drives the piston to advance at a rate N to increase the pressure.

In one embodiment, the device receives a measured pressure value every other periodic time interval, such as a time interval ranging from 0.1 to 2.5 seconds, so the volume change rate and pressure need to be recalculated and adjusted. In one embodiment, the rate is recalculated every 0.5 seconds.

According to a second aspect, the present invention provides a method for detecting a change in position of an airway device having an inflatable seal, the method comprising: comparing the representation One of the inflation seal pressures receives a pressure value and a predetermined pressure value to determine a difference value, and if the difference value is greater than a predetermined amount at a predetermined time interval, the detected airway device position change is displayed.

During medical or surgical procedures, changes in the position of the airway device, such as the airway, may occur and may not be detected (ie, not detected by the patient being monitored). A change in position can result in a extubation that causes the airway arm pocket to accidentally retreat into the patient's throat or airway. However, since the throat volume is generally larger than the trachea, it is possible to detect this recessive extubation by monitoring changes, particularly specific pressure changes, in accordance with the present invention.

In an embodiment, the preset pressure value is the previous pressure value within a preset tolerance of the preselected optimal air pressure value. In other embodiments, the preset pressure value is a preselected optimal air pressure value.

In one embodiment, the predetermined amount is a predetermined ratio of a predetermined pressure value. In one embodiment, the predetermined amount is a preset pressure value of 20%, so when the predetermined pressure value is less than 80% of the received pressure value at a predetermined time interval, the detection indicates that the position change is known.

Typically, the predetermined time is between 15 seconds and 2 minutes, and in one embodiment the predetermined time is 60 seconds.

In one embodiment, the method includes: receiving a first pressure value for indicating an inflation seal pressure, the pressure value being within a predetermined tolerance of the preselected optimal air pressure value; thereafter, Receiving more pressure values periodically during a predetermined time interval; comparing each received pressure value with a predetermined pressure value to determine a difference value; if the difference value is greater than a predetermined amount, starting a timer to perform timing within a predetermined time interval, And if more, at that time The pressure value periodically received before the timer is stopped is not within the preset tolerance range of the preselected pressure value, and the detected position of the airway device is changed.

In other embodiments, it is not necessary to calculate a difference between the received pressure value and the preset pressure value. Instead, it may be necessary to compare the minimum value of the received pressure value with a predetermined predetermined ratio of preset pressure values (eg, 80% of the preset pressure value), and if the received value is less than the minimum value, the timer timer is started. .

According to a third aspect, the present invention provides a method for detecting leakage of an inflatable gas conduit fluid, the method comprising: receiving a pressure value of the inflatable gas conduit; calculating a statistical average of the numerical value The received pressure value is a predetermined number of previously received pressure values; and if the statistical average exceeds a threshold average, the airway device is shown to have fluid leakage.

In one embodiment, the numerical calculation utilizes the received pressure value and the previously received pressure value to represent the rate of change or fluid pressure of the inflated airway. In the best case, the rate of change in volume or pressure corresponds to a change in the pressure increase of the inflatable gas conduit.

The use of fluid leaks to inflate and pressurize the airway device seal can adversely affect the proper functioning of the airway device. Therefore, it is necessary to monitor and detect the inflation fluid leakage as much as possible so that it can be corrected by manual procedures. According to the invention, this object is achieved by monitoring the inflation seal pressure.

During the use of the airway device, it is possible that the airway device has leaked. This leakage may be caused by perforation during surgery or by chronic leakage at the junction of the pressure system. According to the present invention, if the airway is leaked When the device occurs, the leakage can be measured by calculating a statistical average of the numerical values, and the statistical average of the numerical values depends on the previously received pressure value of the corresponding number, that is, the statistical value of the previous received pressure value is compared with a threshold value. For example, the value can be known by calculating the volume change rate or pressure, and the determination manner is the same as the first level of the present invention. If the average is greater than a threshold value, it is necessary to make a significant change in the prior time interval that occurs immediately to increase the pressure to achieve the desired pressure, thereby possibly knowing that fluid leakage may occur.

According to a fourth aspect, the present invention provides a method for detecting leakage of an inflatable gas conduit fluid, the method comprising: periodically receiving a pressure value of the inflatable gas conduit; comparing the received pressure value with a predetermined The minimum pressure value, and if the received pressure value is less than the predetermined minimum pressure value, indicates that the airway device has fluid leakage.

In one embodiment, the preset minimum pressure value is a predetermined ratio of preselected optimal pressure values, for example 50% of the preselected pressure values.

When the patient initially introduces the airway device, inflation and pressure adjustments are made to achieve an optimal air pressure value. Thereafter, the pressure value is monitored periodically to detect a sudden drop in pressure. According to the present invention, if the measured pressure value is less than a predetermined ratio of a preselected pressure value, such as 50%, this indicates that the pressure system is suddenly fluidly drained, thereby detecting leakage.

According to a fifth aspect, the present invention provides a method for detecting an airway pressure system occlusion, the method comprising: receiving a pressure value of the inflatable air conduit and calculating a current activity phenomenon, and if the current activity The phenomenon is less than an activity phenomenon threshold at a predetermined time interval, indicating that the airway device pressure system is blocked.

In one embodiment, the activity phenomenon is calculated by comparing the received pressure value to an ideal or average pressure to calculate a difference value. The activity phenomenon is determined by a statistical comparison of the difference values and a predetermined digital difference value calculated using the previously received pressure value.

In certain situations, solid material can be introduced into the closed volume pressure system of the airway device, which can cause blockages that adversely affect the proper functioning of the pressure monitoring system. When a blockage occurs, the pressure becomes very stable and the normal cyclic pressure changes associated with air ventilation cannot be detected. The invention can detect the pressure system blockage of the airway device, and detect whether the deviation between the average value of the pressure and the ideal value is less than a critical value by a predetermined time interval. In a typical situation, the threshold is less than a general deviation average produced by the breathing cycle for a predetermined time interval.

According to a sixth aspect, the present invention provides a computer readable medium having program instructions, wherein the program instructions are executed in accordance with the methods described in the first to fifth aspects of the present invention.

According to a seventh aspect, the invention provides a device having a processor device, the device configuration being performed in accordance with the method according to the first to fifth aspects of the invention.

In accordance with the present invention, those skilled in the art will be familiar with the methods described in the first, second, third, fourth and fifth levels, individually or in combination, and in a typical situation, the above described method may be performed by a computer processor via software. The method of the invention can also be implemented in a hardware manner.

Other desirable and optional features and advantages of the present invention will be apparent from the description of the appended claims.

In the embodiments of the invention depicted below, the monitoring and control device includes a closed volume pressure system having an airway device inflatable seal. The air ducts described in the examples are examples of airway devices. It will be apparent to those skilled in the art that at least some embodiments may be combined with other forms of airway devices such as a laryngeal mask type airway device. Moreover, in addition to the use of a closed volume system having a number of advantages, other systems for monitoring and controlling the inflation seal pressure of the airway device can be used in at least some embodiments.

1 shows a pressure control and monitoring device 10 according to an embodiment of the present invention coupled to an elastic inflation/deflation gas supply line 12 located in the airway device 14 for maintaining the patient's 16 airway unobstructed.

The airway device 14 includes an airway tube 18. The airway tube 18 has a proximal end 20 for attaching the airway tube 18 to an external snorkel or an anesthetic air supply tube for providing gas to the patient's lungs, and the airway tube 18 has a distal end 22 for insertion into the trachea 24 of a human or animal patient. As shown in Fig. 1, the periphery of the distal end 22 of the tube 18 is surrounded by an inflatable/deflation ring or arm pocket 26 made of a resilient resilient material. The arm pocket 26 is made of a restorative elastically deformable material in an inflated state as shown in Fig. 1, and the arm pocket 26 forms a seal which is interposed between the airway device 14 and the surrounding body structure of the patient 16, such as the tracheal wall 24. .

The structure of the airway device 14 is the same as that of the conventional conventional structure. Suitable gas conduits are, for example, a Porex Soft Seal Tracheal Tube and a LoTrach Tracheostomy Tube.

In a typical situation, as shown in Figure 1, the arm pocket 26 of the airway device 14 It is fixed on the patient and then manually inflated. Thereafter, the pressure monitoring and control system 10 is coupled to the airway device 14 by the inflation/deflation gas supply line 12 of the device 10.

2 is a representative schematic component of a pressure monitoring and control system 10 that includes an air control interface 30 for detachable connection of the inflation/deflation gas supply line 12. An extended resilient connection or extension 12' (Fig. 1) is detachably connected to one end of the control interface 30 and the other end is connected to a one-way valve 12". Thus, the supply lines 12, 12 'A continuous open passage between the pressure system and the inflatable arm pocket 26 of the airway device 14 is provided, and a gas venting mechanism can be provided within the housing of the device 10, the details of which are detailed below.

The gas discharge mechanism comprises a syringe of a type such as a body 32 made of a low friction material, such as PTFE having an open (or tail) end barrel bore for interlocking with the piston 36. The body 32 is secured to a frame and extends in length to a closed (or head) end that is connected in an in-line manner to the gas control interface 30 by an interface connection 40. If the inflation gas is to pass through the straight line between the drum 34 and the inflatable/deflation arm pocket 26 of the airway device 14, the first normally closed solenoid valve V1 must be actuated to be in an open state.

The piston 36 is fixedly secured to a support guide (not shown) to enable the piston 36 to advance forward and backward along the central axis of the lumen within the barrel-shaped lumen 34. As shown in Fig. 3, the piston 36 is pushed by the step motor 44, and the precise direction control of the relative excitation variation of each of the four input terminals is controlled by the motor controller and the drive unit 48. Achieved. Motor controller and drive unit 48 are based on processor The command of 50 (not shown) operates to vary the pressure of the arm pocket 26, changing the volume formed by the enclosed volume system between the syringe body 32 and the arm pocket 26 of the airway device 14. In particular, the arm pocket pressure deviation is adjusted by excluding the gas of the closed volume system, and each adjustment movement unit (corresponding to the step operation of the motor 44) may be, for example, 0.0005 ml. This design greatly improves the accuracy of pressure adjustment.

The device of the present invention measures the immediate pressure of a closed volume system. In particular, the apparatus 10 includes first and second pressure sensors PS1, PS2 coupled to the boundary between the drum outlet port 40 and the normally closed first solenoid valve V1 to monitor the gas pressure in a redundant manner. Therefore, the first and second sensors PS1, PS2 should have the same pressure reading unless there is an error exception. The second normally closed solenoid valve V2 is connected to a supply line between the drum port 40 and the first solenoid valve V1. When the actuation is in an open state, the valve V2 establishes a passage from its open gas end to the supply line, and the supply line is interposed between the drum interface 40 and the first solenoid valve, so that when the valve V1 is closed and non-actuated When the state and valve V2 are in the open actuated state, the right-to-left (backward) movement of the piston 36 in the drum-type internal cavity 34 allows the fresh gas around the flow to flow to the closed volume pressure system. Similarly, when the two valves V1 and V2 are in the same state (V2 is actuated and V1 is in the normally closed state), the left-to-right (forward) movement of the piston 34 of the inner chamber 34 will release excess gas or exhaust gas from the system.

Similarly, when the valve V2 is in the normally closed state and the valve V1 is actuated to the open state, the movement of the piston 36 from right to left (backward) will draw the inflation gas from the arm pocket 26 of the airway device 14 (by deflation). In the same state, that is, the valve V2 is not actuated and the valve V1 is actuated, and the piston 36 is moved from left to right (forward) to inflate and press the inflatable arm pocket 26 of the airway device.

As with conventional application techniques, the processor 50 of device 10 issues a sequence of signals to actuate valves V1 and V2 (as shown in Figure 3 below).

Figure 3 is a diagram showing the logic elements used to monitor and control the inflation pressure of the arm pocket 26 of the airway device 14, for example, as shown in Figure 1. The device 10 includes a processor 50 for receiving input signals of the first and second pressure sensors PS1, PS and providing control signals to the motor controller and driver 48, and valves V1 and V2, and outputting signals to the user interface. 52 provides information such as the selected measured pressure value and provides a warning indication that is identical to other method embodiments of the present invention.

It will be apparent to those skilled in the art that processor 50 may include a programmable microprocessor, microcontroller or equivalent device for executing program instructions or implementing a method in accordance with an embodiment of the present invention. In addition, some of the functions of the processor 50 can be implemented by the example hardware disclosed in the World Patent Application No. WO-A-99/33508.

The apparatus 10 operates in the same manner as described in the World Patent Application No. WO-A-99/33508. In particular, the system startup, the safety system and the general system control operations are the same as those described in WO-A-99/33508, and therefore will not be further described herein.

As described above, the device 10 monitors and adjusts the inflation pressure of the airway device arm pocket 26. In a typical condition in which a patient is mechanically ventilated, for example, patient air ventilation is performed through the airway tube 18 by applying a positive pressure, also known as intermittent positive pressure air ventilation (IPPV). Therefore, the device 10 performs a measurement of the change in the midline pressure value pressure. These changes correspond to the breathing cycle, which is approximately 12 cycles per minute for a typical adult anesthetized patient. Therefore, through the gas Whether the respiratory flow of the tube 14 is autonomous or by IPPV will affect the normal cycle of compression/expansion of the arm pocket 26. The compression deformable arm pocket 26 produces a volume change by compression/expansion, which in turn causes a pressure cycle to change.

In the system disclosed in the World Patent Application No. WO-A-99/33508, if the detected pressure difference value is within the allowable zone of the set point (corresponding to the center line), the system does not perform pressure adjustment, meaning that the system does not The above changes will be handled. When the system pressure difference value is detected to be greater than the tolerance, the system will immediately process it, and the system control causes the piston 36 to move immediately to correct the gap for deviating from the set point. However, changes caused by the breathing cycle may cause the pressure of the arm pocket 26 to exceed or fall below the allowable zone set point. Therefore, the pressure of the arm pocket may fall below the pressure required to form the minimum pressure required to cause leakage of secretions that may fall into the airway device, and may also exceed the maximum pressure, posing a risk of injury to the patient.

According to the apparatus of the first embodiment of the present invention described above, FIG. 4 is a flow chart depicting the execution steps of the method for implementing the processor 50 to adjust the pressure of the closed volume system. The method is used to correct the deviation from the ideal pressure beyond the predetermined tolerance zone, and to ensure that the inflation pressure does not fall below the minimum value of the seal formed in the airway. In particular, the rate control method is adapted to the pressure deviation detected by the pressure deviation, and is suitable for the deviation caused by the normal pressure change of the patient's breathing cycle.

The same as the conventional system boot process, the method to establish the inflatable airway device arm 26 of the bag 14 of the pressure P ₁ to be controlled after a preset tolerance region of the preselected set point pressure value started. It will be apparent to those skilled in the art that the operator may select a set point value from a possible midline pressure value for a particular condition, such as a child, adult male or female, in a typical condition. In this embodiment, the operator selects the applicable arm pocket pressure values in 20, 30, 50, and 50 mmHg, but it should be noted that other pressure values may also be applied to the device.

Thus, in step 405, the method first device 10 by the first and second pressure sensors PS1, PS2 corresponding to a receive arm inflatable bags of pressure P ₁ measured pressure values. In step 410, the method compares the measured pressure value P ₁ with the selected set point value S to determine a difference value (P ₁ -S), and considers whether the difference value is within a predetermined tolerance range (eg, S+/ -0.5 mmH2O (mmHg)). If it is within the preset tolerance zone, step 410 determines that the measured pressure value P _{1 is} within the preset tolerance zone. Next, the method returns to step 405 and waits for the next sampled pressure value. On the other hand, if step 410 determines that the measured pressure value P _{1 is} not within the set point value preset tolerance zone, the method proceeds to step 415 to determine the pressure change rate to correct the difference value. In particular, in the illustrated embodiment, step 415 calculates a value for the speed N employed by the piston 36 driven by the stepper motor 44, where N is the stepper motor steps per second, using the formula: Where: N series steps P ₁ is the actual measured pressure S system set point or ideal pressure * represents the multiplication operation R system predetermined adjustment constant

Regulatory constants are used to relieve pressure regulation and prevent system changes.

In one embodiment, the speed N value is defined based on the stepper motor 44 The large value threshold value T is the number of steps N per second. In one embodiment, T is 2000 steps per second. Such a speed limit delays the reaction time, ensuring that the pressure does not exceed or fall below the allowable zone. Therefore, if the value N calculated in step 415 exceeds the threshold value, the number of steps selected is the threshold value T instead of the calculated motor speed N.

Next, in step 420, the method determines whether the sampled pressure P ₁ is greater than the set point value to determine the moving direction of the piston. If the step 420 determines that the pressure P _{1 is} greater than the set point, the method proceeds to step 425 where a signal is sent to the stepper motor controller and driver 48 to control the stepper motor 44 to drive the piston 36 at the speed N to the drum cavity 34. Retreating to increase the volume reduces the pressure of the closed volume pressure system and reduces the pressure of the inflatable arm pocket 26. Alternatively, if the step 420 determines that the pressure P _{1 is} less than the set point, the method proceeds to step 430 where a signal is sent to the stepper motor controller and the driver 48 controls the stepper motor 44 to drive the piston at a speed N in the barrel-type lumen 34. Advance to reduce the volume, increase the pressure of the closed volume pressure system, and increase the pressure of the inflatable arm pocket 26.

After performing step 425 or 430, the method returns to step 405 and waits for the next sampled pressure value. In a typical situation, the P ₁ pressure value is periodically received at typical time intervals, such as every 0.5 seconds. In other embodiments, the sampling time interval can be different other values, and the piston speed calculation can also be changed frequently. Since the speed is recalculated to correct the pressure when half of the previous calculation steps are performed, the pressure sampling rate every 0.5 seconds is matched with the above formula (1). The volume change rate/pressure is proved to be good.

Therefore, the method of the embodiment of the present invention periodically samples the system pressure and responds to the pressure by the reaction speed, which depends on the measured pressure and the best. The difference between the air pressure (such as the set point) and is limited by the preset maximum threshold value. Therefore, the pressure regulation of the closed volume system can affect the pressure change by changing the piston speed continuously. The method drives the piston 36 at a high speed when the difference between the actual and set point pressures is high, and the piston speed decreases when the measured pressure approaches the set point pressure. Therefore, the pressure change rate control can be adjusted to relieve the pressure by responding to the detected pressure deviation. Gradually changing the pressure to correct deviations from the ideal pressure avoids the problems caused by impatience.

Figure 5 is a flow chart depicting the steps performed by the processor 50 to detect the change in position of the inflatable airway device 14 in accordance with other embodiments of the present invention. As noted above, changes in airway devices, such as airway position, may occur during medical or surgical procedures. This change may result in extubation, causing the airway arm pocket to inadvertently exit the patient's throat or upper airway. The throat volume is generally larger than the trachea, so sudden tube extubation can be detected by monitoring a significant pressure drop. In typical conditions, the reduced pressure is set to 20% or higher.

The same as the conventional system boot process, the method to establish the inflatable airway device of the arm 14 of the bag pressure P ₁ is to be controlled after a preset tolerance region of the preselected set point pressure value started. It will be apparent to those skilled in the art that the operator may select a set point value from a possible midline pressure value for a particular condition, such as a child, adult male or female, in a typical condition. In this embodiment, the operator selects the applicable arm pocket pressure values in 20, 30, 50, and 50 mmHg, but it should be noted that other pressure values may also be applied to the device.

Thus, at step 505, the method is first received by the first and second pressure sensors PS1, PS2 arm at a display inflatable bags of pressure P ₁ measured pressure values. At step 510, the method compares the measured pressure value P ₁ with the selected set point value to determine a difference value, and considers whether the difference value is within a predetermined tolerance range. If the step 510 determines that the measured pressure value P _{1 is} within the preset tolerance zone, the method returns to step 505. In addition, if the step 510 determines that the measured pressure value P _{1 is} not within the preset tolerance zone, the method proceeds to the second phase of step 515.

At step 515, the method receives a further one of the first and second pressure sensors of the device 10 to measure the pressure value P ₂ . Step 520, comparing the more measured pressure value P ₂ with the previously measured pressure value P ₁ to determine a difference value, and considering whether the difference value is greater than a predetermined amount, in this example the predetermined amount is 20% of the previously measured pressure value P ₁ . The predetermined amount may be a previously measured value of a different ratio, for example, between 15% and 30%, a set point value corresponding to a ratio, or a fixed predetermined pressure difference value (for example, 10 to 25 mmHg).

If step 520 determines that the difference value is not greater than 20%, the method returns to step 515. Alternatively, if step 520 determines that the difference value is greater than 20% of the previously measured pressure value P ₁ (or other set point value or fixed pressure difference value), the method proceeds to step 525.

It will be apparent to those skilled in the art that if the measured pressure value and the previous pressure value are not compared to determine a difference value and then the difference value and the threshold value are compared, the measured pressure value P ₂ and a predetermined minimum pressure may be compared in step 520. The value achieves the same effect. For example, the minimum pressure value may be 80% of the previous predetermined pressure value P ₁ . Then in this example, step 520 compares P ₂ with 80% of P ₁ to determine if P _{2 is} less than or equal to 80% of P ₁ , and whether to proceed to step 525.

In step 525, the method starts a timer. In this embodiment, the timer setting execution time is 60 seconds, but in other embodiments, Use other timers to perform timing settings, such as between 15 seconds and 2 minutes.

While the timer is started at step 525, the method proceeds to step 530 to receive the next measured pressure value P _N . In step 535, the method compares the next measured pressure value P _N with the set point value to determine a difference value, and considers whether the difference value is within a predetermined tolerance range. If step 535 determines that the measured pressure value P _{N is} within the set point value preset tolerance zone, the method proceeds to step 540 where the timer ends. The method then returns to step 515. Alternatively, if step 535 determines that the measured pressure value P _{N is} not within the preset tolerance zone, the method proceeds to step 545 to consider whether the timer has expired. If the timer has not expired, the method returns to step 530 to receive the next measured pressure value P _N (as in the typical case described above, the pressure value is sampled at, for example, a periodic time interval of 0.5 seconds). Alternatively, if the timer has expired, the method proceeds to step 550 to determine that the airway device has a significant position change and initiates an "error location alert."

Step 550 initiates the error location alert mode by providing one or more signals on the user interface 52 on the device 10 to provide an audible and/or video alert.

After step 550, the method ends, but may be repeated when the airway device 14 is repositioned with the device 10 new settings.

In some embodiments, the method depicted in FIG. 5A can be combined with an automated method of issuing a warning method if the measured pressure is less than a significant amount, such as a 50% optimal air pressure value or higher. This method is detailed in the embodiment described in Figure 7 below.

Figure 5B is a flow chart depicting the algorithm implemented by the method of Figure 5A.

6 is a flow chart depicting a step for detecting fluid leakage performed in the first method of the processor 50, which is typically a gas from a closed volume pressure system of an inflatable gas conduit. The steps of execution are the same as in other embodiments of the invention.

Leakage of pressurized gas or other fluids used in inflatable seals of airway devices can also affect the proper functioning of the pressure monitoring and control system 10. Therefore, the leakage is monitored and detected, so that the leakage can be manually adjusted in time. According to the invention, this object can also be achieved by monitoring the pressure of the inflatable seal.

Leakage is highly likely to occur in the airway device during use of the airway device. This leakage may be due to perforation during the procedure or a leak that slowly occurs at the junction of the pressure system. According to the present invention, if leakage occurs when the airway device is used, it can be detected by calculating a statistical average value, that is, a statistical average of the value and the threshold value, depending on the value corresponding to each previously received pressure value. For example, the volume change rate or pressure can be calculated as a value in the same manner as described in the first aspect of the present invention. If the average is greater than the critical value, it means that a significant change occurs in the immediately preceding time period, so it is necessary to increase the pressure to the ideal pressure, thus indicating that fluid leakage may occur.

This numerical comparison can be seen in the implementation of Figure 6, during and/or after the conventional system setup procedure of device 10. In particular, in step 605, the method first receives a measured pressure value P _N indicative of the pneumatic arm pocket pressure P ₁ from the first and second pressure sensors PS1, PS2. In step 610, the measured pressure value P _{N is} compared to the selected set point value to determine a difference value, and whether the difference value is within the predetermined tolerance level. If step 610 determines that the measured pressure value P _{N is} within the set point value preset tolerance zone, the method sets a value N to zero in step 615. Then, returning to step 605, the next sampled pressure value is received after a predetermined sampling period. In addition, if the step 610 determines that the measured pressure value P _{N is} not within the preset tolerance zone, the method proceeds to step 615.

In step 620, the method determines the volume change rate and pressure to correct the difference value. In particular, in the depicted embodiment, step 615 calculates a value as the speed at which the stepper motor 44 drives the piston 36, which corresponds to the number of steps N per second of the stepper motor, as calculated using equation (1) above.

At step 625, the method determines if the measured pressure value P _{N is} greater than the set point or the optimal air pressure value. If the measured pressure value P _{N is} greater than the set point or the optimum air pressure value, it means that the set point pressure is exceeded and no leakage occurs. In some embodiments, the method ends here. However, in the current embodiment, if step 625 determines that the measured pressure value P _{N is} greater than the set point or the optimal air pressure value, the method sets the value N to a negative number in step 628. If so, if the measured pressure value P _{N is} less than the fixed point pressure value, the value N is a positive number and the method proceeds to step 630.

Step 630 calculates a rate of change of volume / pressure of the statistical average (e.g., average value calculation made), for example, the statistical average from the previous line of the previous 20 samples a predetermined digital samples (e.g., the N-P _N calculated previously is worth 19 samples and calculation The N value of the pressure value). In step 635, the method compares step 630 to calculate the resulting average and preset thresholds. The threshold value is a minimum value mean value indicating an abnormal pressure reduction in the normal use of the pressure-regulated response patient. In the preferred embodiment, the threshold value is 400, representing a normal average value N (which may be aerated (positive number), deflated (negative number) and stable (static) steps) within a 10 second breathing cycle. The operator can adjust the threshold value, set a lower value for detecting small leaks, or set a higher value to detect larger leaks.

If step 635 determines that the average value is less than the threshold, the method returns to step 605. Alternatively, if step 635 determines that the average value is greater than the threshold, the method proceeds to step 640.

In step 640, it is indicated that the leaking pressure system of the airway device has leaked, so that a "leakage warning" is initiated.

The initiation of the leak alert in step 640 can provide an audible and/or visual alert by providing one or more signals on the user interface 52 on the device 10. These warning signals are used to prompt the operator to check the connection of the closed volume pressure system to compensate for the effects of gas loss.

After step 640 is completed, the method ends. The method can repeat the step execution after the device 10 is reset.

In the method of Fig. 6A, the average calculated value N is determined and compared with the critical value. In other embodiments, the value that can be used may be the average measured pressure value. The method of using the average value is less affected by normal pressure fluctuations in the breathing or air ventilation cycle.

Figure 6B is a flow chart depicting the algorithm implemented by the method of Figure 6A.

Figure 7 is a flow chart depicting the steps performed in other methods of the processor 50 for detecting fluid leakage, typically in the typical case of a gas from a closed volume pressure system of an inflatable gas conduit, the method of performing The steps are the same as in other embodiments of the invention.

As previously mentioned, perforation during use of the device of the present invention, such as during surgery, may cause leakage of the airway device. According to the invention, if leakage occurs In the case of an airway device, it can be monitored by detecting a sudden drop in the value of the inflation airway pressure below a minimum pressure. In a typical condition, the minimum pressure value can be 50% of the ideal pressure or a pressure set point of the airway device.

The method steps of FIG. 7 can be performed after the setting of the device 10, for example, when the device is in normal use.

At step 705, a measured pressure value for the pressure P _N of the corresponding inflatable arm pocket 26 is received by the first and second pressure sensors PS1, PS2 of the device 10.

In step 710, the received measured pressure value P _{N is} compared with the preset pressure value. In this embodiment, the set point value S corresponding to 50% of the selected set point value is determined to determine whether P _{N is} less than 50%. If step 710 determines that the measured pressure value is greater than 50% of the set point value, the method returns to step 705. Alternatively, if step 710 determines that the measured pressure value is less than the 50% set point value, the method proceeds to step 715 to initiate a "leak alert" indicating leakage of the gas charging system of the airway device.

The leak alert implementation in step 715 can provide an audible and/or video alert by providing one or more signals on the user interface 52 on the device 10. The alert may be the same or a different alert than step 63 of Figure 6. These warning signals are used to prompt the operator to check the connection of the closed volume pressure system to compensate for the effects of gas loss.

After step 715, the method ends. The method can repeat the step execution after the device 10 is reset.

Figure 8 is a flow chart depicting the pressure system blocking execution steps performed by the processor 50 for detecting an inflatable gas conduit, the method of performing the same steps as other embodiments of the present invention.

As described above, solid matter may be accidentally introduced into the closed volume pressure system of the airway device 14 installed in the pressure monitoring and control device 10 under certain conditions, thereby causing clogging (this clogging generally occurs in the gas supply line 12), As a result, the monitoring and control device 10 does not function properly. When the blockage occurs, the pressure will be stable, and the pressure change of the normal cycle of air ventilation cannot be measured. The present invention detects during a predetermined time interval if the pressure distance ideal value (herein referred to as "activity phenomenon") deviation average value is less than a threshold value, indicating that the airway device pressure system is blocked. In a typical situation, the threshold is generally less than the average of the pressure deviation over a predetermined period of time due to the breathing cycle.

The method periodically calculates the activity phenomenon value, which is calculated every 1.25 seconds in a typical situation. In step 805, the first PS1 and second pressure sensor 10 of the receiving apparatus, PS2 display one of the inflatable bags 26 pressure arm immediate pressure value P _N. In step 810, a difference value between the measured pressure value and the preset (or pre-calculated) average pressure value is determined. The difference value in step 815 is stored in a circular buffer in which the current and predetermined number of previously calculated pressure difference values are stored (in this example, the number of values stored is 10). In step 820, the activity phenomenon is calculated as an average value and stored in a circular buffer.

This average value indicates whether respiratory circulation activity is normal. Especially during normal operation, during the patient's spontaneous breathing or during the use of mechanical air ventilation, cyclic positive and negative pressure fluctuations occur near the set point value. During each cycle, the pressure difference value distribution near the set point is about 0.5 to 3-5 cm H2O (1 mmHg = 1.395 mm H2O).

The method uses a timer to determine whether the degree of activity is below a criticality The value is used to indicate if a blockage has occurred during the equivalent time period. In a typical situation, when the activity phenomenon is lower than a low threshold (for example, a low threshold value of 3), the timer is started for 3 minutes (180 seconds), and the set execution time, such as 1 to 5 minutes, may be changed in time. When the timer has expired without re-setting, a blocking alert is initiated. However, if the timer still performs timing and the activity exceeds the above high threshold (for example, 8), the timer resets or ends the execution timing.

The blocking alert can provide an audible and/or visual alert by providing one or more signals on the user interface 52 on the device 10. This signal is used to inform the operator to see the blocking situation of the closed volume pressure system.

Referring to Figure 8, step 825 determines if the timer has expired, and if so, in step 830, a blocking alert is set to initiate a blocking alert. After step 830, the method compares the current active phenomenon value with the high critical value. At step 835 it is determined if the activity is greater than the high threshold. The high threshold is used to indicate that the active phenomenon is in a normal pressure fluctuation state of the breathing cycle. If the activity phenomenon is greater than the high threshold value, it means that there is no blockage, and the activity of the gas passing through the gas supply line 12 is normal. In one embodiment, the high threshold is 8. Therefore, if step 835 determines that the activity phenomenon is greater than the high threshold, step 840 resets the timer to continue the timing.

On the other hand, if step 825 determines that the timer is still timing, step 850 resets the blocking alert flag. And in step 855, it is determined whether the current active phenomenon is greater than the low critical value. In one embodiment, the low threshold is 3. If the step 855 determines that the activity phenomenon value is greater than the low threshold value, indicating that the activity phenomenon is lower than the normal activity phenomenon represented by the high threshold value, the method is Step 860 resets the timer to continue the timing.

The device and method use an airway device such as a gas conduit arm pocket pressure controller. Any device in combination with the various aspects of the present invention can provide the following functions: a) performing a pressure correction at a controlled rate in response to periodic changes in pressure generated by abnormal breathing conditions to maintain pressure within a desired range (to prevent overruns) a condition below the desired pressure range); b) monitoring the leakage of the pressure system and issuing a warning if the leak is detected; c) monitoring the deviation from the position of the correct airway device, and sending a warning to avoid the trigger if the wrong position is detected Or completely extubated; d) monitoring for pressure system blockage, warning if a blockage is detected.

These functions can be implemented in conjunction with prior art devices such as those disclosed in the World Patent Application No. WO-A-99/33508.

The device performs control execution functions via microprocessor 50 including, but not limited to, diagnostic inspection, motor and valve operation and control, and pressure measurement. In a typical situation, the device includes a user interface 52 having an indication pressure and a warning image display, and the control unit has an interface output data for performing advanced monitoring and control so that different commercial software can also use the observation data.

In the normal adjustment mode, the system pressure is sampled every 0.5 seconds, so that there is enough time between each sample to perform the comparison with the set point pressure, and the control signal is sent to the motor controller in a continuous pulse mode to drive the piston to remove the closed volume system gas. , adjust the pressure to the appropriate set point pressure.

A system for all of the above aspects of the present invention can greatly assist an anesthesiologist during an anesthesia procedure during a procedure. In particular, this A system provides a synchronized processing algorithm to perform airway device status operations in an immediate or near-instant manner, and provides an audible and/or visual alert alert anesthesiologist to perform the corresponding operations.

The present invention has been described above with reference to a preferred embodiment. However, it is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧ device

12‧‧‧ airway device

12’‧‧‧Extension line

12"‧‧‧ check valve

14‧‧‧airway device

16‧‧‧ Patients

18‧‧‧airway tube

20‧‧‧ Near end

22‧‧‧ distal

24‧‧‧ trachea

26‧‧‧arm bag

30‧‧‧Control interface

32‧‧‧ body

34‧‧‧Drum type cavity

36‧‧‧Piston

40‧‧‧Export interface

44‧‧‧stepper motor

48‧‧‧Motor controller and drive unit

50‧‧‧ processor

52‧‧‧User interface

1 is a schematic perspective view of a device according to an embodiment of the present invention, which is connected to an airway device connected to a patient; FIG. 2 is a schematic block diagram depicting the device of FIG. 1; and FIG. 3 is a block diagram depicting Figure 1 is a control and monitoring device for use in accordance with an embodiment of the method of the present invention; and Figure 4 is a flow chart depicting a method of performing a method for controlling airway device pressure in accordance with a first embodiment of the present invention; FIG. 5B is a flow chart depicting a method for performing a method for detecting a change in position of an airway device according to a second embodiment of the present invention; FIG. 6A and FIG. 6B are flowcharts depicting a third embodiment of the present invention for detecting Method for performing airway device pressure system leakage; FIG. 7 is a flow chart depicting a method for performing a method for detecting leakage of an airway device pressure system according to a fourth embodiment of the present invention; and FIG. 8 is a flow chart A method of performing the method for detecting an obstruction of a pressure system of an airway device in accordance with a fifth embodiment of the present invention is depicted.

10‧‧‧ device

12‧‧‧ airway device

12’‧‧‧Extension line

12"‧‧‧ check valve

14‧‧‧airway device

16‧‧‧ Patients

18‧‧‧airway tube

20‧‧‧ Near end

22‧‧‧ distal

24‧‧‧ trachea

26‧‧‧arm bag

Claims (8)

A method for monitoring an inflation seal pressure of an airway device, the method comprising the steps of: receiving a pressure value indicative of an inflation seal pressure; comparing the received pressure value to a preselected optimal pressure value; If the difference value between the received pressure value and the preselected pressure value is greater than the preset tolerance, the inflation seal pressure is changed to decrease the difference value; wherein the rate of the change pressure step is determined according to the received pressure value and the optimal value A difference value between the air pressure values; wherein the rate is dependent on a difference between the received pressure value and the optimal air pressure value, the rate producing a delay corresponding to or greater than a period of time of the inspiratory or expiratory time interval. The method of claim 1, wherein the step of receiving a pressure value is performed periodically during a predetermined time interval. The method of claim 2, wherein the predetermined time interval is between 0.1 and 2.0 seconds. The method of claim 1, 2 or 3, wherein the rate of change of the pressure step is dependent on a square of the difference between the received pressure value and the preselected pressure value. The method of claim 1, 2, or 3, wherein the changing the pressure step is to change the volume of the closed volume pressure system, wherein the volume change rate is proportional to: Where: N is the volume change rate; P ₁ is the actual measured pressure; S is the set point or ideal pressure; * is the multiplication operation; and R is a regulation constant. The method of claim 1, wherein the rate of change of the pressure step is more limited to a predetermined threshold rate. A computer readable medium having program instructions, wherein the program instructions are executed in accordance with the method of any one of claims 1 to 6. A device having a processor device, the device configuration being performed according to the method of any one of claims 1 to 6.